The Caspian Sea is a volcanic depression. Into it flow the waters of
the Volga, the Ural, the Kour, the Kouma, the Jemba, and others.
Without the evaporation which relieves it of its overflow, this
basin, with an area of 17,000 square miles, and a depth of from sixty
to four hundred feet, would flood the low marshy ground to its north
and east. Although it is not in communication with the Black Sea or
the Sea of Aral, being at a much lower level than they are, it
contains an immense number of fish--such fish, be it understood, as
can live in its bitter waters, the bitterness being due to the naptha
which pours in from the springs on the south.

The crew of the "Albatross" made no secret of their delight at the
change in their food the fishing would bring them.

"Look out!" shouted Turner, as he harpooned a good-size fish, not
unlike a shark.

It was a splendid sturgeon seven feet long, called by the Russians
beluga, the eggs of which mixed up with salt, vinegar, and white wine
form caviar. Sturgeons from the river are, it may be, rather better
than those from the sea; but these were welcomed warmly enough on
board the "Albatross."

But the best catches were made with the drag-nets, which brought up
at each haul carp, bream, salmon, saltwater pike, and a number of
medium-sized sterlets, which wealthy gourmets have sent alive to
Astrakhan, Moscow, and Petersburg, and which now passed direct from
their natural element into the cook's kettle without any charge for
transport.

An hour's work sufficed to fill up the larders of the aeronef, and
she resumed her course to the north.

During the fishing Frycollin had continued shouting and kicking at
his cabin wall, and making a tremendous noise.

"That wretched nigger will not be quiet, then?" said Robur, almost
out of patience.

"It seems to me, sir, he has a right to complain," said Phil Evans.

"Yes, and I have a right to look after my ears," replied Robur.

"Engineer Robur!" said Uncle Prudent, who had just appeared on deck.

"President of the Weldon Institute!"

They had stepped up to one another, and were looking into the whites
of each other's eyes. Then Robur shrugged his shoulders. "Put him at
the end of a line," he said.

Turner saw his meaning at once. Frycollin was dragged out of his
cabin. Loud were his cries when the mate and one of the men seized
him and tied him into a tub, which they hitched on to a rope--one of
those very ropes, in fact, that Uncle Prudent had intended to use as
we know.

The Negro at first thought he was going to be hanged. Not he was only
going to be towed!

The rope was paid out for a hundred feet and Frycollin found himself
hanging in space.

He could then shout at his ease. But fright contracted his larynx,
and he was mute.

Uncle Prudent and Phil Evans endeavored to prevent this performance.
They were thrust aside.

"It is scandalous! It is cowardly!" said Uncle Prudent, quite beside
himself with rage.

"Indeed!" said Robur.

"It is an abuse of power against which I protest."

"Protest away!"

"I will be avenged, Mr. Robur."

"Avenge when you like, Mr. Prudent."

"I will have my revenge on you and yours."

The crew began to close up with anything but peaceful intentions.
Robur motioned them away.

"Yes, on you and yours!" said Uncle Prudent, whom his colleague in
vain tried to keep quiet.

"Whenever you please!" said the engineer.

"And in every possible way!"

"That is enough now," said Robur, in a threatening tone. "There are
other ropes on board. And if you don't be quiet I'll treat you as I
have done your servant!"

Uncle Prudent was silent, not because he was afraid, but because his
wrath had nearly choked him; and Phil Evans led him off to his cabin.

During the last hour the air had been strangely troubled. The
symptoms could not be mistaken. A storm was threatening. The electric
saturation of the atmosphere had become so great that about half-past
two o'clock Robur witnessed a phenomenon that was new to him.

In the north, whence the storm was traveling, were spirals of
half-luminous vapor due to the difference in the electric charges of
the various beds of cloud.